Conservation of the wildcat (Felis silvestris) in Scotland

Summary

The isolated Scottish wildcat (a subpopulation of the European wildcat (Felis silvestris)) was once widespread across Great Britain, but restricted to the north-western Highlands in the late 19^th century. After a recovery in the first half of the 20^th century, the population declined again in recent decades. Today, the wildcat in Scotland is at the brink of extinction. The current population estimation ranges from 30 to 430 individuals, with a further decreasing trend. Threats to the wildcat in Scotland are hybridisation, disease transmission from and competition with (feral) domestic cats, prey number fluctuations, predator control, accidental killing by dogs, in snares or by poisoned baits, road accidents and habitat loss. Hybridisation is considered the major threat to the survival of the wildcat in Scotland and recent data suggest that this threat is accelerating.

To prevent the final disappearance of the wildcat from Scotland, Scottish Wildcat Action (SWA) is implementing the Scottish Wildcat Conservation Action Plan (SWCAP). The work of SWA focusses on five Priority Areas (PAs), where it aims to reduce threats and conserve population nuclei. SWA employs a Trap-Neuter-Vaccinate-Release (TNVR) programme for feral cats, encourages responsible cat ownership, engages with landowners to improve land management practices, collects chance sightings of wildcats, feral cats and hybrids and monitors the remnant populations, mainly by means of camera trap surveys. The most recent winter surveys conducted in all five PAs in the time span of 2015–2018, revealed that only 20% of individuals pictured were wildcats, but 80% (unneutered) hybrids or domestic cats. Research on such an elusive and rare species as the wildcat is difficult and expensive. The low abundance of wildcats and the fact that there is now a continuum from domestic cats to pure wildcats (a hybrid swarm) in Scotland is an additional hindrance to research and monitoring.

Up to now SWA has completed 8 (20.5%) of the total 39 Actions of the SWCAP, 8 (20.5%) Actions have made significant progress, 21 (54%) have been progressed but still need a significant amount of work and 2 (5%) have made only limited progress. We evaluated the achievements of four SWCAP Projects out of 18 as being “good” regarding the progress, ten as being “satisfactory” and four as “not satisfactory”. In October 2018, the SWCAP was revisited and the priority conservation actions were evaluated by the SWCAP Steering Group. We recommend the implementation of an adaptive management scheme with a more consistent monitoring of the progress and the effectiveness of the Projects and Activities of the SWCAP. Based on recent findings, it is crucial to ask the question as to whether the general approach of the SWCAP will enable the saving of the wildcat in Scotland.

Hybridisation was recognised by SWA as the main threat and its mitigation was the most important activity of the SWCAP. In the five PAs surveyed in 2017/18, the total ratio of wildcats to unneutered hybrids was almost 1:6. Hybrids have become so common that wild-living cats in Scotland show a hybrid swarm structure, hence a continuum from domestic cats to pure wildcats. Such a situation has not been observed in any Felis silvestris population in continental Europe, where the domestic cat abundance is also high. Although the biological and ethological aspects of hybridisation of wildcats with domestic cats are not fully understood, it is evident that the situation in Scotland is different.

All the robust information available indicates that the wildcat in Scotland is at the verge of extinction. Based on the available information, we consider the wildcat population in Scotland to be no longer viable. The number of wildcats is too small, the hybridisation too far advanced and the population too fragmented. We therefore conclude that it is too late to conserve the wildcat in Scotland as a standalone population.

But we still recommend that efforts are made to save as much of the gene pool of the Scottish wildcat population as possible. We reason that (1) the recovery of the wildcat in Scotland will only be possible with the support of reintroduction/reinforcement projects, and that (2) the remaining “pure Scottish wildcats” (based on a rigorous genetic protocol) should be combined with wildcats from continental Europe. Both, reintroduction projects or reinforcement of remnant nuclei should be considered. This requires a rigorous suppression of feral cats and hybrids in areas of reinforcements, and the removal of feral cats in areas of potential reintroduction. The SWCAP has already proposed some activities relating to reintroduction and/or reinforcement (e.g. advancing the captive breeding programme and preparing an EU LIFE project that includes conservation breeding). We recommend revising the SWCAP under the paradigm of reinforcement/reintroduction and developing a new spatial concept for the restoration of a viable wildcat (meta-) population in Scotland also including potential wildcat habitats outside existing PAs.

Monitoring and understanding wildcat ecology are important and related activities that should be given higher priority. A better understanding of wildcat ecology and behavior, and their relation to hybrids and feral domestic cats, is crucial and would be best addressed in cooperation with wildcat research and conservation groups from continental European countries, in order to understand the particular situation in Scotland. Appropriate morphological and genetic identification schemes have been developed in the frame of the SWCAP and should become the standard for monitoring of wildcats across Scotland. We recommend conducting surveys based on a robust protocol in all areas where it is speculated that wildcats may still persist, and to continue the monitoring of wildcats, hybrids and feral cats in PAs. We consider the ratio of wildcats : hybrids to be the most important indicator for the constant assessment of the status of the wildcat. Considering the efforts and the achievements so far, responsible cat ownership, the control of feral cats and removing the hybrids especially in the remnant wildcat areas of Scotland, seems to be the major challenge in wildcat recovery across the UK. The history of continental wildcat populations, some of which are presently expanding, demonstrates that wildcats can also maintain their genetic integrity also in landscapes with high densities of domestic cats. However, small remnant or initial reintroduced populations are likely to be much more vulnerable to hybridisation and may require stronger management interventions to prevent hybridisation than a large vital population.

Introduction

The European wildcat Felis silvestris was classified as Least Concern in the regional IUCN Red List assessment in 2007 (Hermann et al. 2007). However, with regard to Scotland, the only region in the British Isles where the species has survived, the authors noted: “The Scottish wildcat is scarce and declining, and is currently listed as Vulnerable on the IUCN Red List of Threatened Species. It may warrant uplisting to a higher category of threat.” Today, the wildcat in Scotland is at the brink of extinction. Scottish Wildcat Action, a multi-partner project supported by Scottish Government is implementing the Scottish Wildcat Conservation Action Plan (SWCAP) to prevent the final disappearance of the wildcat from Scotland. The present SWA programme started in 2015 and will end in 2020. In spring 2018, the SWCAP Steering Group approached the IUCN SSC Cat Specialist Group with regard to an evaluation of the situation of the wildcat in Scotland and the implementation of the conservation activities so far.

The review was done based on the scientific literature and available reports. We are grateful to Alice Bacon (RDSVS, University of Edinburgh), Allan Bantick (SWCAP Steering Group Chair), David Barclay (RZSS/SWA Cat Conservation Project Officer), Peter Cooper (Derek Gow Consultancy Ltd.), Roo Campbell (SWA Priorities Area Manager), Martin Gaywood (Policy & Advice Manager, SNH), David Hetherington (Cairngorms National Park Authority), Kerry Kilshaw (WildCRU), Andrew Kitchener (NMS), Kenny Kortland (FCS/FES) and Helen Senn (RZSS) for providing documents and information or for answering our questions. We are also obliged to the participants of the SWCAP SG workshop in Perth, 10 October 2018, and to our wildcat colleagues Marianne Hartmann and Lea Maronde for comments on the report.

History and present status of the wildcat in Scotland – an overview

History of the wildcat in Great Britain

The Scottish wildcat is believed to be a descendant of continental European wildcat ancestors which arrived in Britain via the land bridge to continental Europe approximately 10,000 years ago (Yalden 1982, Easterbee et al. 1991, Kilshaw 2011). In Britain, it has been used in clan heraldry since the 13^th century and is part of its mythology (Kilshaw 2011). The wildcat was once widespread across Great Britain except on the larger offshore islands (Taylor 1946, Easterbee et al. 1991, Kilshaw et al. 2015). In the 18^th century, its population began to decline, but possibly, the wildcat had disappeared already from southern England already in the 16^th century (Langley & Yalden 1977). During the 19^th century, the decline of the wildcat population continued and accelerated (Langley & Yalden 1977, Easterbee et al. 1991). From 1800–1870 the wildcat went extinct in Wales, the whole of England and many counties of Scotland. It only persisted at low numbers and never went extinct in remote areas of the counties Invernessshire, Ross and Cromarty, Sutherland, Argyllshire and Caithness, in the northwest of Scotland (Fig. 2.1.; Taylor 1946, Langley & Yalden 1977, Easterbee et al. 1991, Harris et al. 1995). The smallest population size was reached around 1914 just before the First World War (Langley & Yalden 1977, Easterbee et al. 1991).

Persecution as vermin (trapping and shooting), hunting for sport and fur and habitat loss were the main causes for the dramatic decline of the wildcat from 1800 onwards (Langley & Yalden 1977, Easterbee et al. 1991, Hubbard et al. 1992, Kitchener 1992a). In many counties of Great Britain, the wildcat was previously hunted for sport during mediaeval times. It also suffered from persecution as it was accused of preying on lambs and chickens (Langley & Yalden 1977). From the mid-19^th century many sport hunting estates were established and the number of gamekeepers increased (Easterbee et al. 1991). Gamekeepers persecuted wildcats as part of management to increase numbers of trophy species, such as grouse and pheasant, (Balharry & Daniels 1993, McOrist & Kitchener 1994). This heavy pressure led to local extinctions and was a major threat especially to small, isolated populations (Easterbee et al. 1991). The wildcat may have survived in north-western Scotland because of its remoteness and the lower human population density resulting in low levels of persecution, rather than high habitat quality (Easterbee et al. 1991). As late as 1984-1985, 274 Scottish wildcats were killed according to the Game Conservancy’s Vermin Returns from only 40 estates (Easterbee et al. 1991).

During the First World War 1914–1918, persecution decreased as gamekeepers were conscripted, and reforestation started thereafter (Easterbee et al. 1991). The wildcat population in Scotland responded quickly and started to recover (Taylor 1946, Easterbee et al. 1991, Hubbard et al. 1992, McOrist & Kitchener 1994). From 1919–1935, wildcats recolonised north-central Scotland and by 1946 they had recolonised much of the range known to be occupied today (Langley & Yalden 1977, Easterbee et al. 1991, Kitchener 1992, Hetherington et al. 2016). In the 1960s, the population expansion slowed down and halted as most of the suitable area north of the central industrial belt in Scotland (stretching east-west from Edinburgh to Glasgow) was occupied (Arnold 1984, Easterbee et al. 1991). The Scottish wildcat survey conducted by the Nature Conservancy Council (NCC) from 1983-1987 showed an extensive distribution of the wildcat north of the central belt with no evidence of wildcats further south (Easterbee et al. 1991; Fig 2.2). The high urbanisation and industrialisation of the central belt seems to form a firm boundary and limit further spread towards the south (Anonymous 1990, Easterbee et al. 1991, Hubbard et al. 1992, Kitchener 1992). Habitat loss, persecution and hybridisation with feral cats are further possible reasons for the restriction of the wildcat to northern Scotland (Kilshaw et al. 2015; Chapter 2.3).

Comparing the distribution range from 1988 with historic records indicates a considerable expansion of the occupied area from the assumed “relict” population of 1915 (Balharry & Daniels 1993; Fig. 2.3). The systematic wildcat survey from 1983-1987 by the NCC assessed 34% of the geographically distinct wildcat populations in Scotland to be declining, 58% as stable and 8% to be increasing (Easterbee et al. 1991). Wildcat population density was generally low, even in suitable habitat. The status of the Scottish wildcat was considered best in the northeast, east and south-west, and worst in the north-west of Scotland where the wildcat had persisted in the early 20^th century (Easterbee et al. 1991).

Present status of the wildcat in Scotland

The Scottish wildcat survey conducted by Scottish Natural Heritage (SNH) from 2006-2008 confirmed that ildcats were more abundant in the east than the west of Scotland, as already observed in the 1983-1987 survey (Fig. 2.4.; Davis & Gray 2010).

The wildcat distribution has changed little since the late 1980s, except in the west of Scotland where it has been decreasing and become increasingly fragmented (Davis & Gray 2010, Yamaguchi et al. 2015). Wildcats were present within the valleys extending from the high plateaux in areas such as the Cairngorms, Sutherland, and central highlands and along coastal areas (Davis & Gray 2010). Most Scottish wildcat records were collected in Aberdeenshire, Invernessshire, Morvern, Perthshire and the central Highlands. Wildcat strongholds were indicated in the Cairngorms, the Black Isle, Aberdeenshire and Ardnamurchan (Davis & Gray 2010). No records were found in areas of the northwest Highlands, Wester Ross, parts of north Stirlingshire and on Scottish islands, except some sightings from Mull, Arran, Orkney and Lewis, which were misidentifications (Davis & Gray 2010). The wildcat appeared to be stable in the north and east of Scotland, with localised populations around Ardnamurchan and Morvern (Davis & Gray 2010). The authors found indications that core areas of “Scottish wildcats” still exist and that the purest Scottish wildcat populations most likely persist in the north and west of Scotland, especially in coastal areas with low pet and feral domestic cat numbers (Davis & Gray 2010). However, recent camera trapping surveys revealed more wildcat-looking cats in the east of Scotland. However, this could possibly be due to higher cat population densities in the east or due to less survey effort taking place in the north and west of Scotland (K. Kilshaw, pers. comm.).

The distribution range of the wildcat was estimated at 43,842 km² based on data from 1980-2003 and the “trend in habitat” assessed as increasing from 1990-1998. However, the amount of inhabited area and the “range trend” were unknown (JNCC 2007). Based on camera trapping throughout northern Scotland, Kilshaw (2015) predicted the occupancy probability of feral domestic cats, hybrids and wildcats based on habitat (Figs. 2.5, 2.6). The habitat model did not make any predictions on wildcat populations or on their current presence.

Density of wildcats was estimated at 1 individual/100 km² in the west to 68 individuals/100 km² (including wildcats and hybrids) in the north-east (Table 2.1.).

Threats

Characteristics of the Scottish Wildcat

The wildcat has a yellowish-brown or greyish-brown to dark grey coloured fur with 7-11 dark brownish black body stripes (Fleming 1828, Taylor 1946, Kilshaw 2011). From nose to tail tip, the female wildcat in Scotland measures 73-89.5 cm and males 82.3-98.1 cm, respectively (Kilshaw 2011, Balharry & Daniels 1998). The tail is thickly furred, club-shaped, with 3-5 black rings, has a blunt black tip and a mean length of ~27cm (Fleming 1828, Anonymous 1987, Kilshaw 2011). Males weigh 3.3-7.26 kg, females 2.4-4.7 kg, respectively (Taylor 1946, Kilshaw 2011, Campbell 2015). Scottish wildcats can be distinguished from domestic cats based on their colouration and pelage markings, and dead specimens are distinguished by the relative length of the intestines and skull and mandible characters and biometrics (Table 2.2; Kitchener 1992, Kitchener et al. 2005, Kitchener & Daniels 2008).

Kitchener et al. (2005) analysed the morphological differences between wild-living cats in Scotland based on 20 pelage characters combined with 40 skull parameters and the intestinal length. Wild-living cats were classified into three groups, with Group 1 cats furthest away from domestic cats, supposed to have little or no recent domestic cat ancestry. Seven of the 20 pelage characteristics were identified to significantly differentiate domestic cats and wildcats (Fig. 2.9., Table 2.3.). Kitchener et al. (2005) suggested using Group 1 to identify Scottish wildcats phenotypically, based on the identified seven key pelage characteristics. A strict scoring system for dead or immobilised cats (cats scoring 19 or more and with no score of 1 for any pelage characteristics), and a relaxed scoring system for field identification (cats with scores of 14 or more and with no score of 1 for any of the seven pelage characters) was suggested (Table 2.3), with the aim of identifying cats with a high proportion of wildcat characters, which may foster the restoration of the wildcat population (Daniels et al. 1998, Macdonald et al. 2004, Kitchener et al. 2005, Kilshaw et al. 2010, Macdonald et al. 2010). For (suspicious) hybrids fulfilling most of the pelage characteristics of a wildcat, genetic confirmation was advocated (Kilshaw et al. 2010).

Prey selection

The preferred prey of the Scottish wildcat is the European rabbit, Oryctolagus cuniculus, notably an introduced species. Where rabbit population desitites are high, as in eastern Scotland, they can form up to 70% of the diet (Corbett 1979, Delahay et al. 1998, Kilshaw 2011). In western Scotland, where rabbit population densities are low, staple food is voles and mice (Delahay et al. 1998, Scott et al. 1993, Kilshaw 2011). Alternative prey species are birds, reptiles, invertebrates, fish and carrion (Hewson 1983, Corbett 1979, Kilshaw 2011). In Glen Tanar Estate, Aberdeenshire, wildcats mainly preyed on rabbits, especially young ones and those with myxomatosis. Rodents, shrews and birds were of less importance and gamebirds were only occasionally preyed on (Corbett 1979, Easterbee et al. 1991). However, in Drimnin estate, west Argyll, wildcats mainly preyed on rodents and birds (Hewson 1983). Balharry & Daniels (1998) found that small mammals (field voles, bank voles, wood mice and common shrews) were the most frequent prey species in Scotland, but considering biomass, lagomorphs were more important, followed by birds. There is little evidence for wildcat predation on lambs and roe deer fawns and it is considered to be uncommon (Fleming 1828, Easterbee et al. 1991, Balharry & Daniels 1998).

Habitat use and requirements

The main habitat requirements of the wildcat are shelter and prey availability (Easterbee et al. 1991, Kilshaw 2011). In Scotland, they inhabit conferous and broadleaved woodlands, grassland and scrub patches (Easterbee et al. 1991, Silva et al. 2013a). The wildcat is not primarily a forest animal, but forest is an important habitat for the wildcat (Campbell 2015). Woodland and dense gorse or juniper thickets are used for shelter and denning (Easterbee et al. 1991, Kilshaw 2011, SNH no date). Open areas are used for hunting, but woodland, scrub or stream edges are important for moving (Corbett 1979, Easterbee et al. 1991, Daniels 1997, Macdonald et al. 2004, SNH no date). In the east of Scotland, wildcats prefer margins of moorlands, pasturelands and woodlands, but in the west they are mainly found in uplands with rough grazing, moorlands with limited pastures and gorse bushland (Easterbee et al. 1991, Daniels 1997, Macdonald et al. 2004). Presence of European rabbit, high rodent diversity and the prevalence of large grassland areas are positively associated with wildcat occurrence (Silva et al. 2013a). Heterogeneous areas have higher prey diversity and abundance, and the presence of both rabbits and rodents may mitigate the effect of prey fluctuations (Silva et al. 2013a, b; Chapter 2.3.).

In contrast, areas with few grassland patches, secondary watercourses, heather moorland and higher elevations were associated with wildcat absence (Silva et al. 2013a, b). Easterbee et al. (1991) showed that wild-cats selected mosaics consisting of open fields and reforested patches, and Daniels (1997) found that in northeast Scotland, “wild-living” cats preferentially used woodland and stream edges and avoided open pasture and heather moorland. Corbett's (1979) study, also in the northeast of Scotland, found that Scottish wildcats preferentially used forested habitat, but avoided mature pine forests, and the study of Scott et al. (1993) in the west of Scotland reported that wildcats showed a preference for woodland and scrub habitat in relation to its availability within their home ranges. Wildcats are generally absent from areas of intensive cultivation (Easterbee et al. 1991), urbanised regions and human habitations (Kilshaw 2011, SWT 2011), although use of farm structures such as hay barns has been observed in various radiotracking studies, especially during winter months (Corbett 1979, Daniels 1997, Kilshaw unpub. data).

Scottish wildcats occur generally at low altitudes, usually not above 650 m, but may be found up to 800 m (Easterbee et al. 1991, Daniels 1997, Macdonald et al. 2004). Favourable environmental conditions for the wildcat are found at altitudes of 100-650 m with a rather cool climate (mean minimum annual temperature of -5-10 C°) and with low human population densities (<1 inhabitant/km²; Easterbee et al. 1991, Daniels 1997, Kilshaw et al. 2016). Industrial and urban infrastructures are considered barriers limiting the movement of the Scottish wildcat (Easterbee et al. 1991, JNCC 2007; Chapter 2.1, 2.3). However, wildcats may tolerate human disturbance through habituation. They can be found close to human settlements, possibly due to the proximity to lowland areas harbouring higher prey abundances or providing additional food sources (Sliva et al. 2013b). When the population density of wildcats is low, they may be attracted to feral cats and domestic cats living in the vicinity of human settlements during the mating season (Silva et al. 2013b). Less elevated areas with a connected mosaic of habitats (mix of woodland and grassland), abundant prey (rabbits and rodents(, shelter and dens should be priorities for conservation efforts (Silva et al. 2013a, Kilshaw et al. 2016, SWT no date).

Spatial ecology

Wildcats are solitary hunters and territorial using olfactory marks (scats, urine, and cheek rubbing) for marking and communication (Corbett 1979, Kilshaw 2011). Male home ranges overlap with the home range of one or more females, but female home ranges are exclusive (Corbett 1979, Macdonald et al. 2004). Home range size varies with habitat quality and prey availability (Easterbee et al. 1991, Corbett 1979, Daniels 1997, Scott et al. 1993). Where rabbit abundance is low and wildcats rely on small rodents, as on the west coast of Scotland, home ranges were found to be 8-18 km² based on VHF radio tracking (Scott et al. 1993, Kilshaw 2011). Corbett (1979) found in northeast Scotland, where rabbit population density was high, home range sizes were c. 1.8 km². Based on more recent GPS radio tracking studies, home ranges of wildcats were estimated at 15–25 km² (Campbell 2015, K. Kilshaw, unpub. data). Subadult male wildcats disperse further and faster than females, sometimes moving up to 55 km before settling down. They are able to travel more than 10 km per night (Hubbard et al. 1992, Scott et al. 1993).

Reproduction and demography

Rock cairns, large logging piles, clearfell, tree roots, fox dens, badger setts, fallen debris, hay barns or empty rabbit warrens are used as dens (Corbett 1979, Campbell 2015, Kilshaw 2011, Kilshaw unpub. data, SNH no date). Wildcats are sexually mature when they are approximately one year old (Kilshaw 2011). Wildcats usually mate and conceive in January to March and the litter is born in April to May (Matthews 1941, Kitchener 1995, SNH no date). If the first litter is lost early, females may have a second oestrus at the end of May or beginning of June (Matthews 1941, Daniels et al. 2002, SNH no date). Wildcats give birth to 1-8 kittens (average litter size: 3-4; Matthews 1941, Daniels et al., 2002, Macdonald et al. 2004, SNH no date). Young wildcats disperse at 5-6 months old (usually in September/October; Kitchener 1995, SNH no date). In Scotland, only 7% of wildcats live longer than 6 years in the wild. Maximum age for females was observed to be 10 years, and for males, 8 years (Balharry & Daniels 1998).

Phylogenetic and taxonomic characteristics

Taxonomy

The wildcat diverged from other felid branches around 6 million years ago (Macdonald et al. 2010). In the 18^th century, the European wildcat Felis silvestris, the domestic cat Felis catus and the African wildcat Felis lybica were all considered separate species (Balharry & Daniels 1998). Ragni & Randi (1985) concluded, based on craniometric traits, that European wildcat, domestic cat and African wildcat belong to one polytypical species Felis silvestris. According to Driscoll (2011), the wildcat includes six subspecies: F. s. silvestris, F. s. lubica, A. s. cafra, F, s, ornata, F. s. bieti and F. s. catus. Kitchener et al. (2017) recognise in their revised taxonomy of the Felidae seven species in the genus Felis: F. bieti, F. catus, F. chaus, F. lybica, F. margariata, F. nigripes and F. silvestris. The wildcat occurring in Europe and Anatolia (F. silvestris) and the wildcat occurring in Africa and Asia (F. lybica) are classified as different species.

The wildcat in Scotland was originally described as a different species Felis grampia (Miller 1907), based on a cat specimen from Invermoriston (Balharry & Daniels 1998). Although the etymology of the name is nowhere explicitly stated, it is likely derived from the Scottish mountain range, the Grampian Mountains. Later on, the Scottish wildcat was classified as Felis silvestris grampia a subspecies of the European wildcat because of its darker colour and different stripes making them apparently distinct from the wildcat of central Europe, Felis silvestris silvestris (Miller 1912, Easterbee et al. 1991). However, pelage characteristics vary across European populations with a cline of distinctly striped animals in the west to faintly striped animals in the east (Kitchener et al. 2017). There is also individual variation among animals in Scotland. Therefore the justification for a separate subspecies is rather weak (Easterbee et al. 1991). Kitchener et al. (2017) suggested two subspecies of F. silvestris: F. s. silvestris distributed across Europe including Scotland, Sicily and Crete, and F. s. caucasica occurring in the Caucasus and Turkey. Thus, the Scottish wildcat is no longer recognised as a separate subspecies (Kitchener et al. 2017). Also according to Kilshaw et al. (2015), the wildcat in Scotland is a subpopulation of the European wildcat Felis silvestris silvestris.

Genetics of the wildcat in Scotland in comparison to the continental populations

The relatively low number of haplotypes found in wildcats from Scotland probably reflects the isolation of the British wildcat population from continental Europe by rising sea levels approximately 7,000-9,000 years ago (Yalden 1999), but could also be the result of recent population decline and drift (A. Kitchener, pers. comm.). For comparison, Nussberger (2013) found in 400 samples from Switzerland, France and Germany 45 distinct haplotypes forming two clusters (Fig. 2.11.), based on two primer pairs of the control region yielding sequences of 350 bp and 200 bp, respectively. The two clusters can be attributed to domestic cats and wildcats, with 31 and 14 distinct haplotypes, respectively. Steyer et al. (2018) obtained a 110-bp sequence of the control region also using two primers and 1071 individual cats from Germany and Luxembourg. They found 19 haplotypes in domestic cats and 13 in wildcats.

Haplotype networks have been published for continental European populations (Nussberger 2013, Steyer et al. 2018), and are presently being investigated also for the wild living cats in Scotland allowing then a comparison with published European reference data.

Wildcats in Scotland had already lower genetic variability based on samples collected 25 to almost 60 years ago compared to wildcats from continental Europe assessed recently. With an estimated population size of as low as 115–130 (Kilshaw 2015) or 200 (95% CI = 30–430; Mathews et al. 2018), continuing hybridisation (Senn & Ogden 2015, Senn et al. 2018) and long-term isolation, it should be expected that the genetic variability may even be lower today.

Recent conservation initiatives and projects

Conservation planning and initial projects

The dawn of contemporary efforts to conserve the wildcat in Scotland was the extensive survey by the NCC from 1983–1987 (Chapter 2.1), published by Easterbee et al. (1991). But it took another 13 years until the first comprehensive analysis and action plan was published (Macdonald et al. 2004).

The Scottish Wildcat: Analyses for Conservation and Action Plan 2004

The report 'The Scottish Wildcat: Analyses for Conservation and an Action Plan' (Macdonald et al. 2004) provided an overview of the status, natural history and threats to the wildcat in Scotland, and presented recommendations for conservation actions. Hybridisation and persecution were identified as the main threats to the wildcat in Scotland. The authors concluded that the protection of individuals with classical wildcat pelage may not be sufficient to conserve and restore wildcat populations in Scotland. A major conclusion of their work was that it would be “helpful to separate the question of how individual specimens are defined and diagnosed as wildcats under the law from the question of how wildcats may most effectively be conserved and their populations restored.” They proposed a “two-tier system whereby individual cats are defined (and thus legally protected) on the basis of classical pelage, but whereby the viability of their populations is secured through a series of management actions” (Macdonald et al. 2004). The recommended measures included:

3. Recommended actions and legislative changes
   1. To conduct a public information campaign and inform stakeholders about the status and value of the wildcat and the steps needed to conserve the species;
   2. To provide a clear definition for a wildcat to ensure its effective protection, as the legislation did not yet provide a list of criteria to differentiate wildcats from feral cats and hybrids;
   3. To add the wildcat to the list of Priority Biodiversity Action Plan species;
   4. To establish “a system of regional zonation, based on the designation of areas with variable probabilities of containing cats of a certain type, which should be used as a framework within which specific conservation actions could be targeted”;
   5. To agree on a Code of Practice for Wildcat Conservation;
   6. To identify SAWCs, based on the frequencies of occurrence of furthest from domestic cats to conserve the genes most likely representative of pre-Iron Age wildcats from Scotland;
   7. To reduce hybridisation and contact between domestic and wild-living cats;
   8. To apply non-lethal cat control (except removal of cats not meeting criteria) in SAWCs;
   9. To work with veterinarians in SAWCs including proactive and free neutering of domestic cats for cat owners, and an information leaflet for responsible cat ownership to prevent hybridisation and disease transmission;
   10. To work with game-managers within SAWCs and develop non-lethal control methods;
   11. To develop and implement a regular monitoring programme to assess effectiveness of conservation actions;
   12. To not conduct reintroduction at present, but to conduct a feasibility study;
   13. To encourage the stud book for the Scottish wildcat and carefully manage captive individuals.

The “Scottish Wildcat: Analyses for Conservation and Action Plan” by Macdonald et al. (2004), was never directly implemented, but strongly informed the subsequent research, planning and practical activities to conserve the wildcat in Scotland, and most of the reccommendations were taken up in the subsequent projects and initiatives.

Species Action Framework 2007- 2012

The Species Action Framework (SAF) was created in response to the 2004 Scottish Biodiversity Strategy, launched in 2007 by the Government and coordinated by SNH (Gaywood et al. 2016). The SAF “set out a Wildcat in Scotland – Review of Conservation Status and Activities 26 strategic approach to species management in Scotland, together with a list of 32 species (including the Scottish wildcat) for which new, focused effort and resources over five years (2007-2012) could make the most difference for biodiversity” (Gaywood et al. 2016). For the wildcat, five actions were identified at the beginning of the SAF:

1. Provide a robust dataset to clarify the distribution of the Scottish wildcat;
2. Identify potential wildcat strongholds for conservation action;
3. Improve guidance on methods to improve habitat management in potential wildcat areas to encourage a sustainable population;
4. Initiate a programme of wildcat conservation measures to reduce the threat from hybridisation;
5. Raise awareness of the status of the wildcat and establish appropriate partnerships to support coordinated management action for its conservation.

The work funded by SAF comprised three objectives:

1. Identification of the Scottish wildcat and the development of a practical guide for identifying wildcats: SNH commissioned the Wildlife Conservation Research Unit of the University of Oxford (WildCRU) to examine the association between morphological and genetic characteristics of the wildcat in Scotland. Kilshaw et al. (2010) concluded that at least 70% of the specimens collected from free-living populations and held in museum collections were wildcat-domestic cat hybrids or were domestic cats. Based on pelage patterns, three groups of cats were identified (wildcats, domestic cats and hybrids), which could also be distinguished by genetics. Kilshaw et al. (2010) concluded that the pelage characteristics defined by Kitchener et al. (2005) were sufficient to identify wildcat individuals that were genetically different from domestic cats.
2. Development of survey field methods using camera traps and a detailed survey protocol: Camera trapping was tested in the Cairngorms National Park (CNP) in parts of the Seafield Estate and Strathspey, North East Scotland, where predator control was still applied (Kilshaw & Macdonald 2011). Wildcats captured on camera-trap photographs were identified based on the key pelage characters identified by Kitchener et al. (2005). All cats with a score of 14 and with no score of 1 were considered to be wildcats. Out of 13 individually identified wild-living cats, 4 were classified as wildcats, 9 as hybrids and none as feral cats (Kilshaw & Macdonald 2011). Camera trapping was found to be an effective method for monitoring wildcats (Kilshaw & Macdonald 2011).
3. Development of a project to secure the future of the wildcat in the Cairngorms area: Based on the wildcat survey of 20062008, the Cairngorms National Park was considered a good place to test the protocols and practical conservation actions for the wildcat ( Chapter 2.2; Hetherington et al. 2016; see below for more details).

Cairngorms Wildcat Project

The Cairngorms Wildcat Project (CWP) was conducted in the CNP from 2009–2012 and largely funded by SNH under SAF, with additional resources from RZSS and others. The project was informed by a stakeholder conference in 2008 and a partnership of the CNP Authority, SNH, Royal Zoological Society of Scotland (RZSS), Scottish Gamekeepers Association (SGA) and Forestry Commission Scotland (FCS; Hetherington & Campbell 2012, Hetherington et al. 2016). It was a practical trial of targeted conservation actions for the wildcat aimed at securing its future within the CNP. The main objectives, activities and achievements were:

1. Raising awareness of wildcats and their conservation

To raise awareness of the wildcat at the local and wider public level, and public engagement were considered to be crucial for the success of any wildcat conservation project (Hetherington & Campbell 2012, Hetherington et al. 2016). The CWP established a website for up-to-date information about the project and for collecting sighting records. A Facebook page and a YouTube channel were installed and the brand “Highland Tiger” created to raise awareness. The CWP team produced promotional materials, offered educational talks in schools and gave presentations to key audiences (veterinaries, farmers, local cat welfare groups and gamekeepers; Hetherington & Campbell 2012). The awareness of the wildcat increased and the engagement of the public was successful. The “Highland Tiger Fund” received donations of £48,000 (Hetherington & Campbell 2012, SNH 2013, Hetherington et al. 2016).

2. Neutering domestic cats

Special attention was given to domestic cat owners and gamekeepers. The CWP cooperated with the cat welfare charity “Cats Protection” and with the local veterinary community to coordinate the promotion and delivery of neutering and vaccination of pet and feral domestic cats in CNP, in order to lower the risk of hybridisation with and disease transmission to wildcats (Hetherington & Campbell 2012, Hetherington et al. 2016). Feral cats were trapped, neutered and released to the wild (so called TNR approach). A leaflet was produced promoting responsible cat ownership. The CWP cooperated with gamekeepers to establish a practical wildcat-friendly predator control protocol to minimise the risk of harming wildcats, and distributed identification cards for distinguishing wildcats from feral cats (Hetherington & Campbell 2012, Fredriksen 2015). CWP encouraged gamekeepers to use live cage traps for feral cat control rather than snaring or night shooting based on eye-shine (Hetherington & Campbell 2012). Feral cat management was supported by trained Cats Protection volunteers applying TNR within the CNP, and neutering and vaccinating pet and feral domestic cats was promoted through the engagement with local veterinaries and Cats Protection (Hetherington & Campbell 2012, Hetherington et al. 2016). From 20052011 some 7,560 feral and domestic cats were neutered at seven Cairngorms veterinary practices covering parts of the CNP. The neutering of 3,180 cats at these veterinary practices was funded by Cats Protection (Hetherington & Campbell 2012). However, as the number of unneutered cats, as well as the extent of interactions between feral and wildcats in the CNP are unknown, the benefits of TNR cannot be assessed. Nevertheless, there is potential for TNR to continue to be more targeted and to contribute more to wildcat conservation with an increased understanding of wildcat populations (Hetherington & Campbell 2012). TNR depends on the volunteers, which have to be coordinated, trained, motivated and resourced.

3. Working with estates

The collaboration with estates was successful and an effective partnership between conservation and land management interests and with the SGA was built (Hetherington & Campbell 2012, SNH 2013). Improved understanding of wildcat identification among gamekeepers led to the application of more wildcat-friendly control practices of feral cats. The protocol for wildcat-friendly management was promoted by the SGA and adopted locally by gamekeepers. Moreover, a wildcat-friendly predator control option in Wildcat Priority Areas (PA) was created for the Scottish Rural Development Programme (Hetherington & Campbell 2012, Hetherington et al. 2016). However, indiscriminate spotlight shooting (lamping) for controlling feral cats was still applied (Hetherington & Campbell 2012).

4. Researching and monitoring wildcats

Intensive and opportunistic camera trapping was conducted for monitoring wildcats in the CNP, direct sighting reports compiled, and (wild)cat carcasses collected (Hetherington & Campbell 2012). The intensive camera trap study was conducted repeatedly in the five target estates, following the protocol of Kilshaw & Wildcat in Scotland – Review of Conservation Status and Activities 28 Macdonald (2011). Information on feral cat control activities and cat records was collected from the same estates (Hetherington & Campbell 2012). Knowledge about distribution, occurrence and hybridisation of wildcats in the CNP was enhanced and the value of camera trapping to monitor wildcats and hybridisation was demonstrated (Hetherington & Campbell 2012, Hetherington et al. 2016). The extent of hybridisation was found to be high. Camera trapping revealed that wildcats occurred at low numbers in the west (likely reflecting lower prey abundance; A. Kitchener, pers. comm.), but were absent in the east of the CNP. This difference in wildcat occurrence was possibly due to different land and wildlife management practices in the past. The eastern estates were more managed for red grouse hunting and there was hence more intensive predator control.

Hetherington & Campbell (2012) considered the conservation success of the CWP difficult to assess due to the short duration of the camera-trap study. Collaboration between estates, farmers and Cats Protection TNR branches was recommended to be continued, as well as public awareness-raising on wildcat conservation, including targeted information on domestic cat management in the agricultural sector by Cats Protection and vets (Hetherington & Campbell 2012). A closer connection with the agricultural sector could help in identifying incentives for farmers to ensure responsible cat ownership. The effectiveness of the TNR method should be (quantitatively) evaluated, the TNR programme expanded and wildcat-friendly predator control be more widely encouraged (Hetherington et al. 2016). Intensive camera-trap monitoring, possibly in connection with genetic sampling, could be expanded to other areas, guidance on best practice for camera trapping wildcats should be made more widely available and reported wildcat records should be verified (Hetherington & Campbell 2012).

The CWP enhanced the awareness of the wildcat in Scotland locally and nationally, and provided useful feedback on resources required for wildcat management. According to Hetherington et al. (2016) the CWP “… directly contributed to the development and resourcing of ongoing action under Scottish Wildcat Action…”.

Scottish Wildcat Action

Scottish Wildcat Action (SWA) is led by Scottish Natural Heritage. The project is funded by a range of sources including the Scottish Government, the Heritage Lottery Fund Scotland, SNH, RZSS and other partners. The SWA is the major project implementing the Scottish Wildcat Conservation Action Plan (Hetherington et al. 2016).

• Secure at least five stable populations of Scottish wildcat in the wild;
• Improve the understanding of wildcat status, distribution, numbers, genetics and extent of hybridisation;
• Increase local awareness of threats posed by hybrids, feral and domestic cats to wildcats;
• Encourage widely implemented responsible domestic cat ownership in PAs promoted throughout the Highlands;
• Reduce the risk of accidental persecution;
• Have a better understanding of factors affecting wildcats and how land management can benefit population viability (SNH 2013).

The SWCAP was presented in the form of a Logical Framework, summarised in Table 3.1. First actions planned by the SWCAPSG were to conduct further surveys for the definition of PAs for wildcat conservation, to investigate the extent of hybridisation and the threats from feral cats and hybrids with regard to a better understanding of the genetic composition of the remnant populations, to create management protocols for feral cat and hybrid control in the PAs, to evaluate the status of Scottish wildcats in captivity and the requirements for a captive breeding programme, and to establish guidelines to avoid negative impacts on wildcats by forestry operations and development projects (SNH 2013).

The SWCAP is implemented by the Scottish Wildcat Action (SWA), a partnership of 26 key partners and funders (Scottish Wildcat Action, 20.7.2018; Appendix I). The SWA consists of a Steering Group, a Steering Group Chair, a Priorities Area Project Manager, a Communication Co-ordinator and three Project Officers responsible for the management and implementation of conservation actions in delineated PAs (Fig. 3.2). There is also a Cat Conservation Officer based at, and managed by, the RZSS (equivalent to a project officer). Much of the SWA work builds on the experience from CWP (Hetherington et al. 2016).

To implement the SWCAP, SWA focusses on five PAs (Fig. 3.1), where it works with local people and in particular with land managers, veterinarians and volunteers to reduce the risks of hybridisation, disease and accidental persecution. The SWA started with six PAs but Strathavon was given up as no wildcats were detected in this PA. SWA aims to make these PAs a safe place for wildcats by reducing threats by applying a Trap-Neuter-(Vaccinate)-Release (TNVR) programme to feral cats and by encouraging cat owners to neuter and vaccinate pet cats, thus appealing for responsible cat ownership (SWA 2016). To identify wildcats in the field situation, the SWA uses the classical pelage scoring method of Kitchener et al. (2005) with a cut off score of 17. The SWA also engages with land managers to improve land management practices to support wildcat conservation, and conducts intensive camera-trap surveys (SPICe no date). The situation of wildcats in all PAs was assessed through camera-trap surveys before implementing TNVR (SWA 2016). Camera trapping is continuing to identify any changes in cat activity and to estimate wildcat, feral cat and hybrid numbers (SWA 2016). The SWA furthermore compiles chance sightings of wildcats, feral cats or hybrids through the project’s website. Activities and achievements of SWA with regard to the implementation of the SWCAP are summarised in detail in Table 3.1.

Table 3.1. Objectives, Projects, Actions (as presented in the SWCAP; SNH 2013), achievements and milestones of the SWA as evaluated by the SWCAP Steering Group. The main source for the table was an Excel spreadsheet based on the SWCAP LogFrame showing the work and achievements until May 2017, provided by the SWCAP Steering Group. More recent updates on activities conducted and achievements reached provided by the SWCAP Steering Group members until December 2018 were included and the progress of each Action re-evaluated by ourselves applying the categories of the SWCAP Steering Group.

• Completed,
• Work ongoing - significant progress made but not complete yet,
• Work ongoing - progress made, but significant amount of work still to be done,
• Dark orange = limited work so far – the majority of work still to be done.

The leading and partner institutions for each Action are listed in the Logical Framework of the SWCAP (SNH 2013).

Abbreviations:

• BRC = Biological Records Centre,
• CRRU = Campaign for Responsible Rodenticide Use,
• ddRAD = double digest RAD sequencing,
• HFW = Highland Foundation for Wildlife,
• HLF = Heritage Lottery Fund,
• HWP = Highland Wildlife Park,
• NBN = National Biodiversity Network,
• NFUS = National Farmers Union Scotland,
• PTES = People’s Trust for Endangered Species,
• SGA = Scottish Gamekeepers Association,
• SGP = Sharing Good Practice,
• SRDP = Scottish Rural Development Programme.
   

According to the assessment of the SWCAP Steering Group in May 2017 (SWA 2017), 6 (15%) of the Actions were then completed, 6 (15%) had made significant progress, 23 (59%) progressed but still needed a significant amount of work, and 4 (19%) had made only limited progress with the majority of work still to be done. Since this intermediate assessment, further Actions have been advanced or completed, which is captured in the colour shades in Table 3.1 above. According to Table 3.1., 8 (20.5%) of the Actions were completed, 8 (20.5%) made significant progress, 21 (54%) progressed but still need significant amount of work and 2 (5%) had made only limited progress.

Camera trapping surveys

Based on camera-trap surveys in the PAs, the minimum number of wildcats alive and the minimum number of un-neutered hybrids in each PA have been estimated (Table 3.2). Wildcats were identified according to the 17 point pelage-score threshold (R. Campbell, pers. comm.). The genetic analysis show that all sampled wild-living cats are hybrids to a greater or lesser extent and very few reach the 17 point pelage-score threshold (R. Campbell, pers. comm.). Many cats that look like wildcats were not sampled because, up to spring 2018, most of the trapping work has been targeted at cats suitable for TNVR. The sampled cats did not render better genetic results than cats with lower pelage scores (R. Campbell, pers. comm.). Some cats score more than 17 points possibly because “they are the last of a dwindling number of high pelage scoring cats” or because “there is sufficient gene flow from other high pelage scoring cats areas outside of the priority areas” or “simply because breeding among the remaining hybrid cats occasionally throws out high pelage scoring offspring” (R. Campbell, pers. comm.). As an alternative explanation, A. Kitchener (pers. comm.) suggested that this may indicate a breakdown in correlation between genetic and morphological characters owing to high levels of introgression in the hybrid swarm.

Overview on TNVR efforts and achievements

Any cat with a 7PS less than 17 was considered to be a hybrid or feral cat and thus a target for TNVR. The first full season of active TNVR was conducted during winter 2016/17 (Rawling 2017). TNVR was applied in all six PAs to some extent from October 2016 to March 2017 (Rawling 2017). In total, 90 cats were treated/underwent TNVR process during this time span (Table 3.3 & 3.4; Rawling 2017). Over the winter 2017/2018 TNVR was conducted in five PAs simultaneously with wildcat trapping (Rawling 2018). In total 106 animals were treated/underwent TNVR process (Table 3.3 & 3.4). During 2017/2018, “every TNVR site had landowner access permission. Not all estates who gave access for general wildcat survey work also gave permission for TNVR as some preferred to continue their own lethal control methods” (Rawling 2018). As of September 2018, four cats were caught and fitted with GPS collars (K. Kilshaw, pers. comm.), two of which are classed as wildcats on the basis of pelage and two as hybrids (none would pass the genetic threshold for wildcat used for conservation breeding). In late 2018 an additional animal was added, classed as a wildcat based on pelage (genetic test pending; Rawling 2018).

Other initiatives and projects

Wildcat Haven

Wildcat Haven was initiated in 2008/2009 (accessed 07.08.2018). The work has been taking place in Morvern (where also one of the SWA PAs is located) and on Ardnamurchan (Fig. 3.3). More recently Wildcat Haven has been active in parts of Strathbogie, another SWA PA. The project sites were chosen based on wildcat sightings and the characteristics of the landscape, “low human population, low pet cat population, limited development, few roads and a high level of awareness and concern for nature and conservation amongst the local community” (Wildcat Haven 07.08.2018). Wildcat Haven is run by a team led by Director Emily O’Donoghue and Chief Scientific Advisor Dr. Paul O’Donoghue, and including several field vets and field biologists.

The main threat to the wildcat is recognised to be hybridisation. The project “seeks to protect a naturally sustainable population of up to 1,000 pure Scottish wildcats across the West Highlands region of Scotland”. The Action plan as described at Wildcat Haven’s website (07.08.2018) includes:

• Saving the genetically pure Scottish wildcat;
• Removing all feral cats from the region;
• Using humane, neutering based feral cat controls;
• Establishing buffer zones to prevent feral cats returning to the area;
• Removing feline diseases from the entire haven;
• Developing a genetic test for wildcat purity;
• Establishing project owned wildcat reserves across the region;
• Documenting every individual cat in the area;
• Conducting unique research into cat behaviour, genetics and diseases;
• Building wildcat education and awareness worldwide;
• Encouraging reforesting to enhance natural habitat;
• Working alongside local communities and landowners;
• Advising locally owned, low impact, prowildcat tourism;
• Creating new jobs in the local community;

However, the plan per se was not publicised. The project aims to build a safe haven of more than 18,000 km² for wildcats “bolstered by a spine of wildcat reserves acting as strongholds for the species”. Wildcat Haven advertises a wildcat conservation area in the western Highlands: “Ardnamurchan, Sunart, Morvern and Moidart: the ‘inland islands’ now a feral-free Scottish Wildcat Haven”. A buffer zone free of feral cats

should protect the future wildcat population on these peninsulas. Once this area is free of hybrids and feral cats, wildcats will be able to survive and expand naturally (Keane 2017). The project offers free pet cat neutering (Wildcat Haven, 07.08.2018). Feral cats and “lowgrade hybrids” in the project area are reported to be subject to a Trap-Neutering-Release programme. However, Wildcat Haven has not possessed a SNH licence permitting the legal release of feral cats since October 2015 (SNH Licensing, pers. comm.). Blood samples are taken from all captured cats, which are also checked for their health and microchipped. Feral cats and hybrids are neutered. Feral cats or hybrids positive for FIV or FeLV are euthanised. Wildcats are distinguished from hybrids using pelage scores developed by Kitchener et al. (2005) and genetic testing. Wildcat Haven claims to have developed the “First and only comprehensive genetic test for wildcat purity, and the first and only use of that test in the field”.

The project area is monitored by means of camera traps, and some hybrids also by means of radio telemetry (Wildcat Haven, 07.08.2018). No results from the monitoring and field work are made available on the website. A licence return to SNH to cover a licence held for the period 1 October 2012 to 1 October 2015 refers to 58 cats (two hybrids as defined by Wildcat Haven and 56 pet/feral cats) trapped as part of TNVR work in Ardnamurchan. A licence was also held by Wildcat Haven staff from October 2013 to October 2015 to trap, collar and track wildcats but there is no record of any wildcats being tracked. Further information on the work of Wildcat Haven has been sought by email on the 24.09.2018, but no response has been received.